The Chevrolet Volt can very nearly be boiled down to a single a function: range extension. The Volt’s gasoline range-extender is the car’s major technological advantage over other electric vehicles like Nissan’s Leaf, promising consumers freedom from the terror of range anxiety. But how does it actually work? TTAC’s Volt Birth Watch has long asked the question, and GM has assiduously prevented journalists from describing the Volt’s transition from initial EV range to “generator mode.” Until now. The NY Times‘ Lindsay Brooke recently took a pre-production Volt for a spin at the Milford Proving Grounds, and files this report on the generator mode experience:

It takes a few laps of Milford’s twisty, undulating 3.7-mile road course to deplete the remaining eight miles of battery charge. With the dashboard icon signaling my final mile of range, I point the Volt toward a hill and wait for the sound and feel of the generator engine’s four pistons to chime in.

But I completely miss it; the engine’s initial engagement is inaudible and seamless. I’m impressed. G.M. had not previously made test drives of the Volt in its extended-range mode available to reporters, but I can see that in this development car, at least, the engineers got it right.